Origin:
It is believed this beetle is native to Central and South America, but now well established across the U.S. and throughout the world, with occasional occurrences in southern Canada. It’s presence on plants being shipped from California to Japan has caused those shipments to be turned away and quarantines to be put in place.
Biology:
While it is named for and does damage to roses it also feeds on many other ornamental and agricultural plants. Larvae feed on the roots while the adults feed on the foliage, causing the typical damage of weevils as the small notching along the leaf margins. It occasionally causes serious problems in greenhouses. Females deposit more than 200 eggs in masses over a period of several months, gluing them to leaves or into crevices in the bark of trees. Only females are known in this species. Adult beetles or larvae may overwinter. There typically is a single generation, but in warmer regions two generations are possible.
Identification:
Adult beetles are 3/8 to ½ inch long and incapable of flying. The abdomen and wing covers are egg shaped and cylindrical, and the thorax only slightly narrower than the front of the wing covers. Color varies from light gray to brown with heavy darker mottling all over as well as many white patches, and with a lighter band along the sides of the wing covers.
Characteristicts Important to Control:
Control with insecticides is aimed at killing the adult beetles, as the larvae are generally going to be in the soil. Since the adults cannot fly they must crawl up stems and trunks of plants to oviposit, and sticky materials on the lower trunks can trap these beetles. Contact insecticides applied to the foliage when adult beetles are present can be helpful.
